/*  multirec.c - see also diewitherror.c and multisnd.c */

/* compile  $ cc -o multirec.exe multirec.c diewitherror.c */

 

/*                   program      multicast ip  port */

/* useage example $ ./multirec.exe 224.0.22.1 9210  */

 

/* tested with cygwin gcc win32- linux gcc -sun */

 

#include <stdio.h>      /* for printf() and fprintf() */

#include <sys/socket.h> /* for socket(), connect(), sendto(), and recvfrom() */

#include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */

#include <stdlib.h>     /* for atoi() and exit() */

#include <string.h>     /* for memset() */

#include <unistd.h>     /* for close() */

 

 

#include <time.h> /* modified for timestamps */

 

 

 

#define MAXRECVSTRING 255  /* Longest string to receive */

 

void DieWithError(char *errorMessage);  /* External error handling function */

 

int main(int argc, char *argv[])

{

    int sock;                         /* Socket */

    struct sockaddr_in multicastAddr; /* Multicast Address */

    char *multicastIP;                /* IP Multicast Address */

    unsigned short multicastPort;     /* Port */

    char recvString[MAXRECVSTRING+1]; /* Buffer for received string */

    int recvStringLen;                /* Length of received string */

    struct ip_mreq multicastRequest;  /* Multicast address join structure */

 

    if (argc != 3)    /* Test for correct number of arguments */

    {

        fprintf(stderr,"Usage: %s <Multicast IP> <Multicast Port>\n", argv[0]);

        exit(1);

    }

 

    multicastIP = argv[1];        /* First arg: Multicast IP address (dotted quad) */

    multicastPort = atoi(argv[2]);/* Second arg: Multicast port */

 

    /* Create a best-effort datagram socket using UDP */

    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)

        DieWithError("socket() failed");

 

    /* Construct bind structure */

    memset(&multicastAddr, 0, sizeof(multicastAddr));   /* Zero out structure */

    multicastAddr.sin_family = AF_INET;                 /* Internet address family */

    multicastAddr.sin_addr.s_addr = htonl(INADDR_ANY);  /* Any incoming interface */

    multicastAddr.sin_port = htons(multicastPort);      /* Multicast port */

 

    /* Bind to the multicast port */

    if (bind(sock, (struct sockaddr *) &multicastAddr, sizeof(multicastAddr)) < 0)

        DieWithError("bind() failed");

 

    /* Specify the multicast group */

    multicastRequest.imr_multiaddr.s_addr = inet_addr(multicastIP);

    /* Accept multicast from any interface */

    multicastRequest.imr_interface.s_addr = htonl(INADDR_ANY);

    /* Join the multicast address */

    if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void *) &multicastRequest,

          sizeof(multicastRequest)) < 0)

        DieWithError("setsockopt() failed");

 

    /* Receive a single datagram from the server */

    /* Start loop here */

 

int c;

int x1 = 1000000; /* initialize loop variables */

int x2 = 0;

 

while (x2 < x1)

{

/* x1++ */

/* uncomment the line above to have a limit */

if ((recvStringLen = recvfrom(sock, recvString, MAXRECVSTRING, 0, NULL, 0)) < 0)

        DieWithError("recvfrom() failed");

 

    recvString[recvStringLen] = '\0';

 

 

 

time_t tim=time(NULL);  /* get time stamp to print with recieved data */

             char *s=ctime(&tim);

             s[strlen(s)-1]=0;        // remove \n

         /*    printf("it is %s now.\n", s); */

     

    printf("Time Received: %s : %s\n", s, recvString);    /* Print the received string */

 

}

    close(sock);

    exit(0);

 

} /* main */